03 / Setup and migration
What to do after downloading
Installing the client doesn’t mean it’s routing your traffic yet. Start the client and import a subscription or local configuration. Check for parsing errors, then choose a rule mode and policy group. Rule mode follows your configuration to decide what connects directly or through the proxy. Global mode can help with temporary troubleshooting, but it doesn’t guarantee that every app is routed; traffic handling still depends on system proxy or TUN settings.
On desktop, start by enabling the system proxy. Visit a known working site in your browser and check the connection log for the request. If the browser works but another app doesn’t, first check whether that app honors system proxy settings, then consider TUN. On mobile, check VPN permission and connection status first. Avoid changing DNS, rules, ports, and modes all at once; otherwise, it’s difficult to pinpoint the cause of a problem.
Before switching clients, export your configuration and overrides, and note your proxy ports, policy group selections, and any local rules you want to keep. Subscription updates may overwrite direct edits, so use the target client’s override feature for changes you want to retain. Once you’ve verified the new setup, disable startup and system proxy settings in the old client to prevent both from running after a reboot.
Handle client, core, and subscription updates separately. They serve different purposes: the client manages the interface and OS integration, the core handles protocols and network behavior, and the subscription provides server information. When something goes wrong, note the specific error and when it occurred instead of blaming the installer for every issue.
For the full setup process, see the Clash setup guide. To learn how modes, rules, TUN, and DNS work together, continue with the Clash system guide.